From: hkuang <hkuang@google.com>
Date: Tue, 10 Jun 2014 21:48:16 +0000 (-0700)
Subject: Delay decreasing reference count in frame-parallel decoding.
X-Git-Tag: v1.4.0~1400^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e4c5f7e2b6b51417cce2e5acb3fc286a6fc32d24;p=platform%2Fupstream%2Flibvpx.git

Delay decreasing reference count in frame-parallel decoding.

The current decoding scheme will decrease the reference count
of the output frame when finish decoding. Then the application
could copy the frame from the decoder buffer to application buffer.
In frame-parallel decoding, a decoded frame will not be outputted
until several frames later which depends on thread numbers. So
the decoded frame's reference count should be decreased only
after application finish copying the frame out. But due to the
limitation of vpx_codec_get_frame, decoder could not know when
application finish decoding. So use a index last_show_frame to
release the last output frame's reference count.

Change-Id: I403ee0d01148ac1182e5a2d87cf7dcc302b51e63
---

diff --git a/vp9/decoder/vp9_decoder.c b/vp9/decoder/vp9_decoder.c
index 13d79ff..5859859 100644
--- a/vp9/decoder/vp9_decoder.c
+++ b/vp9/decoder/vp9_decoder.c
@@ -211,7 +211,10 @@ static void swap_frame_buffers(VP9Decoder *pbi) {
   }
 
   cm->frame_to_show = get_frame_new_buffer(cm);
-  cm->frame_bufs[cm->new_fb_idx].ref_count--;
+
+  if (!pbi->frame_parallel_decode || !cm->show_frame) {
+    --cm->frame_bufs[cm->new_fb_idx].ref_count;
+  }
 
   // Invalidate these references until the next frame starts.
   for (ref_index = 0; ref_index < 3; ref_index++)
@@ -240,7 +243,9 @@ int vp9_receive_compressed_data(VP9Decoder *pbi,
   }
 
   // Check if the previous frame was a frame without any references to it.
-  if (cm->new_fb_idx >= 0 && cm->frame_bufs[cm->new_fb_idx].ref_count == 0)
+  // Release frame buffer if not decoding in frame parallel mode.
+  if (!pbi->frame_parallel_decode && cm->new_fb_idx >= 0 &&
+         cm->frame_bufs[cm->new_fb_idx].ref_count == 0)
     cm->release_fb_cb(cm->cb_priv,
                       &cm->frame_bufs[cm->new_fb_idx].raw_frame_buffer);
   cm->new_fb_idx = get_free_fb(cm);
diff --git a/vp9/vp9_dx_iface.c b/vp9/vp9_dx_iface.c
index 98faa7f..0738971 100644
--- a/vp9/vp9_dx_iface.c
+++ b/vp9/vp9_dx_iface.c
@@ -40,6 +40,7 @@ struct vpx_codec_alg_priv {
   vpx_image_t             img;
   int                     invert_tile_order;
   int                     frame_parallel_decode;  // frame-based threading.
+  int                     last_show_frame;  // Index of last output frame.
 
   // External frame buffer info to save for VP9 common.
   void *ext_priv;  // Private data associated with the external frame buffers.
@@ -238,6 +239,7 @@ static void init_decoder(vpx_codec_alg_priv_t *ctx) {
   ctx->pbi->max_threads = ctx->cfg.threads;
   ctx->pbi->inv_tile_order = ctx->invert_tile_order;
   ctx->pbi->frame_parallel_decode = ctx->frame_parallel_decode;
+  ctx->last_show_frame = -1;
 
   // If postprocessing was enabled by the application and a
   // configuration has not been provided, default it.
@@ -430,6 +432,15 @@ static vpx_image_t *decoder_get_frame(vpx_codec_alg_priv_t *ctx,
       ctx->img.fb_priv = cm->frame_bufs[cm->new_fb_idx].raw_frame_buffer.priv;
       img = &ctx->img;
       *iter = img;
+      // Decrease reference count of last output frame in frame parallel mode.
+      if (ctx->frame_parallel_decode && ctx->last_show_frame >= 0) {
+        --cm->frame_bufs[ctx->last_show_frame].ref_count;
+        if (cm->frame_bufs[ctx->last_show_frame].ref_count == 0) {
+          cm->release_fb_cb(cm->cb_priv,
+              &cm->frame_bufs[ctx->last_show_frame].raw_frame_buffer);
+        }
+      }
+      ctx->last_show_frame = ctx->pbi->common.new_fb_idx;
     }
   }